1. Field of the Invention
This invention relates to an electrophotographic copying machine having an automatic paper selecting function and particularly to an electrophotographic copying machine having an improved efficiency of operation in an automatic paper selection mode.
2. Description of the Prior Art
In the prior art, there is known an electrophotographic copying machine having an automatic paper selection mode, which comprises a plurality of paper feed portions for containing paper sheets of different sizes and automatically selects a paper feed portion containing paper sheets of a size corresponding to a size of a document to be copied, thereby to perform copy operation using the paper in the selected paper feed portion.
In such an electrophotographic copying machine, if the automatic paper selection mode is selected and a print key is pressed, the size of the document is detected and then a paper feed portion containing paper suited for the detected size of the document is automatically selected, whereby copy operation is performed.
Generally, when a copy operation is to be carried out in the automatic paper selection mode, designated by the operator, the operator expects that the copy is made on plain paper, e.g., white paper. However, in a conventional copying machine, the copy operation in the automatic paper selection mode is permitted irrespective of the type of paper contained in a paper feed portion and accordingly it sometime happens that the copy is made on paper of a type different from that desired by the operator, e.g., color paper.